1. Field of the Invention
The present invention relates to vices and more particularly, to a coaxial concentric double jaw vice.
2. Description of the Related Art
Commercial double jaw vices are basically similar, commonly comprising a fixed jaw and a movable jaw movable along the top side of the vice by a screw rod so that the workpiece can be held firmly by the fixed jaw and the movable jaw. However, after the workpiece is clamped in the vice, an extra pressure must be applied to rotate the screw rod further and to enhance the clamping force. At this time, the workpiece may receive an overpressure, resulting in a bad affect. To avoid this problem, the invention studied the use of a clutch and a driving mechanism in a vice.
Further, conventional multi-power CNC super vices are known using a pressure intensifier to drive a driving barrel in rotating the screw rod to enhance the workpiece clamping force. However, due to the effect of the pressure intensifier, the pressure at the inside of the screw rod and the pressure at the outside of the screw rod may be unbalanced, causing deformation of the screw rod. The invention also eliminates this problem.